Seal assembly in rotary regenerative heat exchanger

Abstract

A seal assembly comprising a seal member which is placed on an end face of a cylindrical and rotatable heat-transferring member by the support of connecting pins secured to a housing member of the heat exchanger, a support plate fixedly placed on a surface of the housing member opposite to and spaced from the end face of the heat-transferring member, and a resilient shield plate which is not joined with the seal member but is fixed at one end to the support plate to extend obliquely such that an acute angle is formed between the support plate and one side of the shield plate to be exposed to a fluid of a higher pressure, until its free end comes into contact with the seal member.

What is claimed is: 
     
       1. In a rotary regenerative heat exchanger including a stationary housing member and a heat-transferring member which is cylindrical and rotatable on the longitudinal axis thereof for heat exchange between a first fluid stream of a relatively high pressure and a second fluid stream of a relatively low pressure, the housing member having a surface opposite to and spaced from a portion of an end face of the heat-transferring member, and a seal assembly for preventing leakage of the first fluid into the second fluid along said end face of the heat-transferring member, said seal assembly comprising: a seal member placed on said end face of the heat-transferring member and loosely joined with said surface of the housing member such that said seal member is movable vertically to said end face;   a support plate fixedly placed on said surface; and   a shield plate of a resilient material fixed at one end to said support plate to extend from said support plate obliquely towards said end face of the heat-transferring member such that an acute angle is formed between said surface and one side of said shield plate to be exposed to the first fluid, the extended end of said shield plate being in sliding contact with said seal member at a surface opposite to said surface of the housing member.   
     
     
       2. A seal assembly as claimed in claim 1, further comprising a back-up plate attached onto the other side of said shield plate to be exposed to the second fluid. 
     
     
       3. A seal assembly as claimed in claim 2, wherein said shield plate is warped such that said one side to be exposed to the first fluid is convex. 
     
     
       4. A seal assembly as claimed in claim 2, wherein said seal member consists of an annular portion and a twisted bar-shaped portion arranged to intersect said annular portion at two regions, both end regions of said bar-shaped portion extending outwardly of the periphery of said end face of the heat-transferring member. 
     
     
       5. A seal assembly as claimed in claim 4, wherein said seal member has two perforations formed respectively in said end regions of said bar-shaped portion, said perforations being elongate in the radial direction of said annular portion, said seal member being joined with said surface of the housing member by two pins arranged respectively to pass through said two perforations. 
     
     
       6. A seal assembly as claimed in claim 2, wherein said shield plate, said support plate and said back-up plate are respectively made from a heat-resisting steel. 
     
     
       7. A seal assembly as claimed in claim 6, wherein said shield plate is fixed to said support plate and said back-up plate with a hard solder.